Shaking head when waking up

[MAM090982]

I have major anxiety, and my nerves have been under major stress lately, so I don't know if this is stress related, or something more serious, but the past few days, when I wake up in the morning, or wake up from a nap in the afternoon, as I am waking, I can feel my head, and body shaking, like vibrating. It is so weird. It stops when I wake up, but it is freaking me out. Is this a normal symptom of anxiety, or something I should be worried about?